Jeffrey Jensen, MD, contextualizes contraceptive efficacy in modern trials

The Pearl Index reported for the newly FDA-approved norelgestromin and ethinyl estradiol transdermal system (Gwyn Lo; Viatris) reflects a shift in how contraceptive efficacy is measured in modern US trials rather than a signal clinicians should find concerning, according to Jeffrey Jensen, MD, MPH, Professor, Obstetrics & Gynecology, Oregon Health & Science University. The discussion continues Jensen's reaction to the FDA approval of the once-weekly patch.^1,2

Approved under the FDA's 505(b)(2) pathway for women with a body mass index below 30 kg/m², the patch reported a Pearl Index of 4.14 (95% CI: 2.77 to 5.95) in the phase 3 Luminous Study.¹

Jensen explained what that figure means in practical terms.

“The way that that would roughly translate is you would expect to see about 4 women out of 100 becoming pregnant a year. The way it is calculated is it is the number of pregnancies that occur in the study divided by the number of evaluable at-risk cycles,” he said, noting that the denominator “has really changed the Pearl Index over the years,” since cycles may be excluded for various reasons while pregnancies never are, he noted.

Jensen emphasized that non-daily administration does not inherently lower pregnancy rates.

“Non-daily administration, and you see the same thing with the rings, does not necessarily imply a lower pregnancy rate than a daily oral combined pill. So users of the methods must use them correctly and consistently to get best results,” he said.

He returned to choice as the central benefit, noting patch-related problems are few and typically occur early in use.

“What I want to make sure is that everyone can choose the thing that they can be most successful with, and that is the bottom line,” Jensen said.

Reference:

1. Fitch J. FDA approves norelgestromin and ethinyl estradiol transdermal patch for contraception. Contemporary OB/GYN. July 29, 2026. Accessed July 31, 2026. https://www.contemporaryobgyn.net/view/fda-approves-norelgestromin-ethinyl-estradiol-transdermal-patch-contraception
2. Fitch J. Jeffrey Jensen, MD, reacts to FDA approval of new contraception patch Gwyn Lo. Contemporary OB/GYN. Published August 2026. Accessed August 4, 2026. https://www.contemporaryobgyn.net/view/jeffrey-jensen-md-reacts-to-fda-approval-of-new-contraception-patch-gwyn-lo